A great effort has been made to develop technologies for cast molding of hydrogel contact lenses with high precision, fidelity and reproducibility and at low cost. One of such manufacturing technologies is the so-called Lightstream Technology™ (Alcon) involving reusable molds and curing a lens-forming composition under a spatial limitation of actinic radiation (U.S. Pat. Nos. 5,508,317, 5,583,163, 5,789,464, 5,849,810, and 8,163,206).The Lightstream Technology™ for making contact lenses have several advantages. For example, reusable quartz/glass molds can be reused, because, following the production of a lens, these molds can be cleaned rapidly and effectively of the uncrosslinked monomer or prepolymer and other residues, using a suitable solvent and can be blown dried with air. Lenses produced according to the Lightstream Technology™ can have high consistency and high fidelity to the original lens design.
However, modern high-volume mass production process for medical devices like contact lenses utilizes re-usable molds in each production cycles. The conventional re-usable contact lens mold consists of a quartz convex base curve and a glass concave front curve. The base curve mold is composed of individually ground and polished quartz, while the front curve mold is composed of high precision press mold and polished glass. The base curve molds must be highly UV transmissive materials such as quartz. In order to ensure consistent lens fabrication, high precision base curve mold shapes are required, and this led to a long lead time in producing a new design for quartz base curve mold because it needs to be individually ground and polished. The long lead-times result in lengthy development cycles and long lead times for mold design and prototyping.
Therefore, there is still a need for new reusable molds for base curve mold that can be produced cost effective and short lead time.